Creamy white icing and juicy bubble-gum balls are just a few of the art tools Heidi Hesse deploys in her museum-size installation on American foreign policy.

Despite its sweet materials, the walk-through work at the Museum of Contemporary Art is a bitter critique of the gap between American rhetoric and American reality, particularly when it comes to the war in Iraq.

An immigrant to the United States from Germany, Hesse conceived of Exporting Liberty as a "metaphorical journey from Europe to America," according to a catalog essay. It does mimic the immigrant voyage over the ocean and into America, but it also goes outward, gauging the effects of U.S. military adventures on the rest of the world. At times, Hesse gets burdened down by highfalutin art-world references, and you occasionally need to consult the catalog essay to deconstruct some heavy-handed symbolism.

But mostly, Exporting Liberty is a wild ride, entertaining and scathing at the same time. Besides the sweet frosting and gum, Hesse has used a wide array of made and found objects: a painted Mylar Statue of Liberty, monochromatic paintings in Homeland Security colors, a militaristic life-size Hummer made of wire and gum, and even a wedding-cake White House.

The multi-part installation is not so much on view at the museum as it is in command of the building. Hesse has divided up the entire gallery space of the rickety old MOCA warehouse, using temporary walls and pillars to create an architectural processional. It begins with an entranceway framed by patriotic, bright-blue walls. Video monitors, rimmed like paintings in old-fashioned carved gilt, hang on each wall, picturing the crashing ocean waves that European immigrants once braved to get to America.

Far ahead, you get a view of the giant-sized Miss Liberty head, painted blood-red. But before you get there, you and the rest of the huddled masses yearning to breathe free learn that America has an admission charge.

Right inside the entranceway is a gumball machine. Pay a dollar, and you get a plastic gumball container filled with pro-America slogans. One of the plastic bubbles, you learn, contains a prize voucher--one lucky patron will win a "painting" of gumballs encased in mesh and hanging on a nearby wall. Success in America, Hesse suggests, is equal parts hard work and hucksterism. For every naïve immigrant in search of streets paved with gold, there's the Barnum sucker born every minute.

The wedding-cake White House, up next, sugar-coats the messages it issues to this gullible public. Ensconced on an Astroturf lawn (a natural for the present anti-environment administration), this treacly seat of power is covered with pretty icing swags and sugar roses. But beware its sour interior. This seemingly sweet White House has, among other sins, reduced our national security to a ludicrous game of Candyland colors.

Beyond her dollhouse-sized White House cake, Hesse plays an insider art joke with Tom Ridge's Homeland Security palette, conflating his simplistic color codes with minimalist paintings. Five "Candychrome" paintings hang along a wall, each acrylic on board saturated by a single Ridge color, re-named American Dream Green, Imperial Blue, Propaganda Red and so on.

Across the way, the giant Hummer--or Gummer, as the gallery workers like to call it--is filled with gumballs in the same Homeland colors. Hesse constructed this faux vehicle in the Toole Shed studios next door, according to museum director Anne-Marie Russell, fashioning a wire frame faithful in every dimension to the real-life monster machine. It's a stand-in not only for the military hardware chugging around Iraq, but for those gasoline-guzzling SUVs and civilian Hummers back home.

In a note, Hesse writes that she got the idea for this piece the day the United States invaded oil-rich Iraq. She was sitting in a Phoenix café, watching SUVs go by, "thinking about the people who were going to die to support the luxurious American ways."

A meditation space in a far corner of the gallery provides a pop quiz on the U.S. Constitution, lately abused by a White House intent on internments without trial. Hesse has written out the familiar preamble in white pastel on a blood-red board, excising the verbs. Small sculptures of these key words sit on a nearby shelf. You can test your knowledge of the fundamental principles embedded in the Constitution by figuring out which verbs go with which bedrock ideals. Hint to the Bushies: "establish" pairs with justice, and "secure" goes with the "blessings of liberty."

The final piece of Exporting Liberty is the proverbial smoky back room where important political decisions are made. Hesse has set up a foosball game populated almost entirely by powerful white males, Condoleezza Rice notwithstanding. The idea is that they control the world, and you don't. Their decisions are not without consequence.

On an adjoining "memorial wall," small American flags, row on row, memorialize each and every American who has died in the war on Iraq. The day I was there, I counted 553. But Hesse is a realist. She's allowed plenty of space, and drilled plenty of extra pegholes, to accommodate more flags as needed.